In the early day of environment monitoring, the measurement is generally done through manual measurement from simple and analog instrument which suffer from the drawbacks like poor accuracy, need of human intervention, associated parallax errors and durability. The rapid development in electronic technology has made reliable integration of smart electronic sensors, processor, and communication device capable of monitoring environmental parameters more favorably. A system for ambient air condition monitoring has been developed as described in this paper. It is based on the embedded system, smart electronic sensor, commercial off-the-shelf (COTS) components, and the terminal monitor by the Graphical User Interface (GUI).

Vapor compression refrigeration cycle (VCRC) is widely used in refrigeration and air conditioning (R&A) systems. Sub-cooling is used to improve the coefficient of performance (COP) of the R&A system by enhancing the cooling capacity. This paper presents various sub-cooling methods, which have been established and applied to enhance the performance of the VCRC.  In a simple cycle of VCRC, the exit of the condenser is at saturated liquid line. Further cooling of the exit condenser to the sub-cooled region can result in an increase in the cooling capacity due to low vapor quality refrigerant entering the evaporator. As a result, the refrigerant absorbs more heat in the evaporator. The lower the quality of the refrigerant entering the evaporator, the higher the cooling capacity that is produced by the evaporator. This cooling capacity improvement results in an increase in the COP. In the present study, four sub-cooling methods are reviewed, which are liquid-suction heat exchanger, dedicated mechanical sub-cooling, integrated mechanical sub-cooling and condensate assisted sub-cooling. The advantages and drawbacks of each method, as well as future research direction in this research domain were discussed in detail.

A point on the psychrometric chart can show 7 properties of air. If two properties are known then 5 other properties can be calculated. Air treatment will change the properties of air conditions. Changes in air condition can be determined by measuring each air properties and plotted on a psychrometric chart. One of the uses of psychrometric analysis is to determine the amount of cooling capacity used in air conditioning systems. To show the condition of the air at any time needed a system that is integrated between the data acquisition device and data display. This research designs and develops applications that are ready to display data and psychrometric charts that can later be integrated with hardware equipped with sensors through an interface. Psychrometric applications are designed using the JavaScript programming language, so they can be opened using any web browser. Psychrometric charts are drawn using iteration calculation methods. Based on the results of data analysis, the difference in value between the results of manual calculations and applications is as follows: wet-bulb temperature (Twb) is 0.27%, Moisture Content (ω) is 0.77%, specific enthalpy (h) is 0.52 %, Specific Volume (v) is 0.28%, Dew-Point Temperature (Tdp) is 0.92%.

Liquefied Natural Gas (LNG) is a complex mixture of low-molecular-weight hydrocarbons with nitrogen as a principal inert impurity. Nowadays, the instrumentation control tools are needed in LNG Commercialization to ensure the LNG is safely transported, while minimizing the energy losses across the network. This research was a preliminary design that used LNG custody transfer control tools referred the ISO 8943:2007 standard. The temperature was measured by thermocouple (Rosemount transmitter 3144 series), while the pressure was measured using pressure transmitter (Rosemount transmitter 3051 series). The simulated signal temperature was done by temperature control box, while the simulated pressure was represented by WIKA pressure calibrator. Data from transmitter was sent to the LabVolt 9063 series that has data acquisition for Software Development Kit (SDK) enabled. Previously, the LabVolt 9063 did not recognized the signal from the transmitter. The SDK software bridged the LabVolt hardware with the LabView software. In the simulated system, temperature alarm will be triggered when the temperature value exceeds 20oC. For simulated pressure, the alarm will respond if pressure value exceeds 30 psi. From the results of this research, the communication between hardware and software worked properly. The data acquisition system was stable during the data collection stage, processing and displaying. In addition, the alarm indicator for both temperature and pressure was met within the threshold value.

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